"I was thinking 'Yeah it's good, but you're still just hanging there'."

The 45 metre high zipwire at Victoria Park allowed the mayor to visit those watching the Olympics on big screens, although his team had not expected him to stay paralysed above onlookers while they photographed his trousers, which were being hitched further up his ankles by the harness.

"The mayor has survived his first zip wire experience relatively unscathed," a spokesperson joked.

"Clearly the judges are likely to have marked the mayor down for artistic impression, and unlike team GB, the mayor may not be winning too many Gold medals today.

"He does however remain unbowed."

David Cameron commented: "If any other politician anywhere in the world was stuck on a zip wire it would be a disaster. For Boris, it’s an absolute triumph."

Those watching the mayor may have been pleased to learn that they at least would not need to hear him, after his transport announcements were cancelled due to low crowds in central London.

Commuters had been forced to listen to Johnson's warnings of high volumesof traffic for several weeks, but Olympic organisers are now facing accusations of killing off retail opportunities after tourists and Londoners stayed away from the capital before what was expected to be a busy period.